Some time we may see group of words that make sense, but they are not senteces, now you may ask that why are not sentense while they are making a full sense.
Let me show this by taking an example below is group of words that make sense and decide yourself if we can call them a sentence.
At house, under the water, in a week, at day time
Such words that we mentioned above are called phrases because they make sense but they don’t have a verb while a sentence is always supported with a Verb this is the main difference between a sentence and phrase.
A sentence has a verb while a phrase don’t have any verb.